1. Field of the Invention
The present invention relates generally to accessories for power hand tools, and more particularly to a battery module for a power hand tool.
2. Description of the Related Art
When charging the battery of a power hand tool, electric energy is continuously transmitting to the battery and a big amount of heat energy is produced to increase the temperature of the battery. There are battery chargers that have heat dissipation means to dissipate heat when charging a battery. However, the heat dissipation means simply dissipates heat from the battery charger, having no significant effect in lowering the temperature of the battery, and the battery under charging may burn out due to excessively high temperature. The high temperature of the battery during its charging mode will also shorten the service life of the battery.